Two-component systems, e.g., for adhesives, sealing compounds, dental impression compounds etc., are composed of two different substances belonging together and stored in a known manner, within two separate storage cylinders for distribution purposes. For processing, both substances are mixed at a predetermined ratio, resulting in a chemical reaction causing their hardening or solidification. Extrusion of both components from the cylinders is effected by simultaneous actuation of feeder pistons, one of which is located within each cylinder, thereby pressing out the substances through the front side discharge openings.
A previously known dual dispenser cartridge of the above described variety (U.S. Pat. No. 4,260,077) comprises a nozzle for each of the two discharge openings, such that two independent strings of substances are being pressed out, requiring subsequent manual mixing thereof. Such a process, however, is inefficient and does not guarantee uniform blending, as is essential for obtaining perfect results. For conveniently achieving thorough mixing of the components, it is therefore common practice to press these through a mixer tube attached to the cartridge cylinders (so called static or flow mixer).
When attaching two-component cartridges to a mixer tube, it is known practice to use special transition members, which may be part of a cartridge dispensing device (e.g., DE-OS No. 35 01 331), or which may be independent thereof (DE-OS No. 34 20 323, FIG. 4 and EP-A No. 0 236 129, FIG. 2). Such configurations, however, involve various, significant disadvantages:
Only single cartridges can be used, so that in use erroneous combinations cannot be excluded (combination of components which do not match or combination of two identical components); PA0 Joining of individual cartridges, transition member and mixer tube, can only be accomplished immediately before the application, resulting in troublesome preparations for each new cartridge; PA0 Individual cartridges are equipped with a front end threaded stud, each of which is to be screwed into one of the internal threads of the transition member. Interlocking of individual cartridges, therefore, is not possible, and as a consequence, this arrangement shows poor mechanical stability, and furthermore, the threaded studs must be concentric, i.e., coaxial with respect to the cylinder axis; PA0 This last mentioned circumstance leads to a large distance between both entry positions (inside thread) of the transition member, thus resulting in extended, convoluted conduction channels from there to the mixer entry, such channels being difficult to manufacture and including a considerable amount of dead volume. Such transition members, therefore, could hardly be manufactured as inexpensive disposable components, thus, resulting again in cleaning problems, etc.
Another known arrangement (FR-A No. 2 399 861) is also based on individual cartridges. A sort of tri-sectional tube serves as a transition member, whereby one section comprises an integrated mixing arrangement and the two other sections are to be pushed onto discharge studs at the cartridges. Such a component, if at all suitable for manufacturing, could hardly be manufactured other than as a rubber-like flexible tube. Such, however, cannot provide a connection of stable shape between the individual cartridges, and the connection to the studs cannot sustain the high pressure developing when pressing out the components.
It is an object of the present invention to eliminate the aforementioned drawbacks of existing products and to provide a readily usable dual cartridge, which permits proper distribution and storage of both associated components already from the processing plant or the filling facility, whereby the mixer tube can be readily attached without difficulties.